There are four types of instrument commonly used. They are the soprano, the concert, the tenor and the baritone ukulele. I would recommend you begin with a soprano, as it is the most common and seems to have the most available associated literature.
You can buy from almost any music shop, but if this is difficult for you for whatever reason, don't hesitate to try online. You are ideally looking for a just above the bottom range soprano, with geared tuners, good intonation (this means that it doesn't sound out of tune the further you play up the neck) and looks pretty sturdy.
There are many brands to choose from and not a lot between them when choosing a starter ukulele, pick something that appeals to you and your price bracket.
Tips for starting the Ukulele
Step 1: Get yourself a cheapish ukulele (not the cheapest, as they will inevitably let you down) fitted with geared tuners, an electronic tuner and a chord book. A good tip is to get a good set of strings as they can make a real difference to the sound you make and will help keep the ukulele in tune, makes like Aquila, D’Addario and Worth will do the trick.
Step 2: Learn how to tune your instrument. Most music for the ukulele is in GCEA tuning and George has filmed this little guide to help: https://www.youtube.com/watch?v=gYgWfJEwRyU
Step 3: Learn and play a few simple chords. Don't rush this.
Step 4: If you haven't returned your instrument to the shop yet and you're still keen, try going online and playing along with the songs on our YouTube channel. Great for building your confidence up in preparation for playing with other musicians.
Step 5: Play with other ukulele players. They are out there somewhere! Quite apart from the fun aspect, they can provide tips on technique etc, which you can then use or reject as you see fit. For free music sheet downloads and to join in with the orchestra for virtual play along sessions head over to our Ukulele Lockdown page.
Step 6: Er, that's it.
Or it would be in an ideal world. There are many paths you can take to your own personal musical nirvana, just remember to enjoy the journey.